Conventional earthmoving or geography altering machines such as track type tractors, motor graders, scrapers, and/or backhoe loaders, have an implement such as a dozer blade or bucket, which is used on a worksite in order to alter a geography or terrain of a section of earth. The implement may be controlled by an operator or by an autonomous grade control system to perform work on the worksite. For example, the operator may move an operator input device that controls the movement or positioning of the implement using one or more hydraulic actuators. To achieve a final surface contour or a final grade, the implement may be adjusted to various positions by the operator or the grade control system.
Positioning the implement, however, is a complex and time-consuming task that requires expert skill and diligence if the operator is controlling the movement. Conventional machines deploy proportional (P), proportional-derivative (PD), proportional-integral (PI), and/or proportional-integral-derivative (PID) controllers to attain position control of various machine implements. Such controllers may be deployed in combination with a Global Positioning System (GPS) receiver on the machine. One such conventional machine control system utilizing a GPS is disclosed in U.S. Pat. No. 6,655,465.
However, such conventional P/PD/PI/PID controllers require frequent retuning of control gain parameters and are not very adaptive to changes in the operating conditions of the terrain or other parameters used in efficient grade control. For example, for each new type of terrain, prior to operation, the controller gain parameters have to be changed for that particular terrain. Such frequent retuning increases latency and requires manual intervention, which increases the operating costs.